一种可能形成POPs途径的初探-气相苯的氯化反应

用串联质谱碰撞室模拟大气环境研究了持久性有机污染物(POPs)形成过程,实验发现,经离子-分子反应可以生成氯苯类化合物。 以中性苯与酰氯为反应物在离子源进行反应,在苯含量为4×10^-3Pa、酰氯含量为4×10^-4Pa时,氯苯的生成量为5×10^-8Pa,远远高于背底浓度5×10^-9Pa。对氯苯类化合物的形成,大气环境明显优于质谱环境,实验结果表明,在大气中经离子分子反应形成POPs是可能的。     

茶多酚的表面性能研究

通过分别测试二碘甲烷、水、甲酰胺等液体在茶多酚上的接触角,并根据van Oss-Chaudhury-Good的组合理论对茶多酚的表面性能进行研究。结果表明茶多酚的表面能随着茶多酚的含量增加而提高;且随着茶多酚的含量增加,儿茶素类物质即含酚羟基类物质的含量进一步增加,形成氢键的几率进一步增大,导致分子之间作用力和氢键力加大,因而使茶多酚的表面能提高。     

顶空气相色谱-质谱法测定玩具中的10种挥发性有机物

建立了检测玩具中10种挥发性有机物(VOC)残留量的顶空气相色谱-质谱(HS-GC-MS)方法。样品经140 ℃、45 min静态顶空后,通过DB-624色谱柱分离和质谱检测,外标法定量。该方法对于不同VOC的定量限(LOQ)均在0.66 mg/kg以下,线性范围为0.001～2.0 μg,平均回收率在79%～106%之间,相对标准偏差(RSD)在0.4%～5.6%之间。该方法具有准确灵敏、简单快速等特点,将其应用于实际玩具样品的检测取得了良好效果。     

大粒径介孔氧化硅微球的优化合成及表征

以非离子型嵌段共聚物为模板剂、正硅酸乙酯为硅源,制备了一种比表面积为712m2·g-1、孔径6.93nm、孔容1.06cm3·g-1、粒径10μm的介孔SBA-15微球,采用扫描电镜考察了各种合成条件对介孔氧化硅微球形貌的影响,对SBA-15介孔微球的合成条件优化和形成机理进行了研究和探讨。结果表明:介孔氧化硅微球的生长可以看作一个由微小溶胶粒子发生渐进聚沉、成长为较大溶胶粒子的过程;共表面活性剂和无机盐的引入对介孔微球的形成具有辅助作用;合成体系的酸度和晶化阶段之前的陈化条件是介孔微球形成的关键所在。在共聚物的盐酸溶液(1mol·L-1)中,不添加共表面活性剂和无机盐,仅控制陈化条件于35℃静置24h,100℃水热处理24h,可得到大粒径的介孔SBA-15微球。     

离子色谱法测定混凝土外加剂中硫酸钠含量

建立了一种离子色谱法测定混凝土外加剂中硫酸钠含量的方法,外加剂试样溶于水中,采用反相柱去除溶液中有机物,进样量25μL。经Dionex IonPac AS18色谱柱分离,用30 mmol·L~(-1)氢氧化钾溶液作流动相,以1.0 mL·min~(-1)流量进行洗脱,按峰面积定量。方法的检出限(3S/N)为3μg·L~(-1)。该方法可实现硫酸钠与氯离子同时测定的优点。在3个浓度水平上对方法的精密度作了考核,测得其相对标准偏差(n=6)均小于1%。用标准加入法,以实样为基体作回收试验,测得回收率在98.7%～100.5%之间。     

三元钴配合物[Co(NCS)2(ql)2](ql=喹啉)的合成及其晶体结构和荧光性质

合成了含异硫氰酸根和喹啉(ql)混合配体的钴配合物[Co(NCS)2(ql)2];利用红外光谱、紫外光谱和X射线单晶衍射等手段对其结构进行了表征;研究了配合物在室温下的荧光发射光谱特性.单晶结构解析结果表明,标题化合物属于单斜晶系,P21/c空间群,晶胞参数为:a=1.486 33(5)nm,b=0.844 44(3)nm,c=1.541 16(5)nm,β=92.093(2),V=1.933 0(2)nm3,Z=4,Dc=1.489 g/cm3,μ=1.116 mm-1,F(000)=884,R1=0.032 2,wR2=0.078 6.配合物中钴离子采用四配位的四面体配位构型,晶体堆积中通过π-π作用形成一维超分子结构.     

Y2O2S∶Er3+，Yb3+的制备及Er3+离子在晶场中的能级分裂

采用沉淀法制备前驱体,通过不同温度合成了上转换发光材料Y2O2S∶Er3+,Yb3+,运用XRD,SEM和上转换发射光谱对其进行表征。结果表明,所合成的Y2O2S∶Er3+Yb3+属于六方晶系晶体,随着合成温度的升高,产物的粒径不断增大,上转换发射光强度逐渐增加。研究Y2O2S∶Er3+Yb3+的上转换发光过程,红光发射和绿光发射分别源于Er3+离子的4F9/2→4I15/2以及2H11/2→4I15/2,4S3/2→4I15/2能级跃迁。利用群论计算了晶场中Er3+离子的能级分裂数目。     

A Study of Spectroscopy on TCAQ Microcrystal

UV-visible absorption spectra of 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ) solution, crystal and evaporated film were, measured. The absorption spectrum of TCAQ solution in DMF had three bands at 287 nm(4.45), 310 nm(4.23) and 350 nm(4.38) respectively; that of evaporated films had one band at 370 nm and that of crystalline powder had four bands at 243 nm, 275 nm, 320 nm and 430 nm respectively. Surface photovoltage spectra of TCAQ microcrystal gave two bands at P₁ (320 nm) and P₂ (430 nm) respectively. The absorption bands were assigned and the energy levels of frontier orbitals were tentatively determined. In addition,the mechanism of hole, production and transportation in crystalline TCAQ was discussed.     

A Novel Amphiphilic Push-pull Ferrocene Derivative: Langmuir-Blodgett Films and Second-order Optical Nonlinearity

We investigated Langmuir-Blodgett(LB) films built from the mixture of an amphiphilic push-pull ferrocene derivative(P) and behenic acid. Langmuir films of P diluted by behenic acid exhibit a very good cohesion, and the mixed films can easily be transferred onto solid substrates. Linear dichroism UV-visible and IR spectroscopy measurements of the mixed LB multilayers confirm that the molecules(P) are oriented to the substrate. The nonlinear optical experiments on the mixed monolayer deposited on the CaF₂ slide showed that P displays efficient optical second harmonic generation(SHG) with a molecular hyperpolarizability (β)h, high as 6.0×10^-29e. s. u..     

Crystallization of Ammonium Nitrate Under Organised Monolayers at Air-Aqueous Interface

The crystallization of NH₄NO₃ under compressed Langmuir monolayers of carboxybe-taine(C₂₂N₃COO^-),C₂₂H₁₅N(CH₂)₃(CH₂)₃COO^--[C₂₂N₃COO^-] and dioleoyl-L-a-lecithin(DOPC) was studied by means of π-A. ΔV-A and fluorescence microscopy (FM). The surface pressure, surface potential and molecular area of C₂₂N₃COO^- were decreased on the NH₄NO₃ solution subphase. The surface pressure and molecular area of DOPC was increased. The surface potential of DOPC was decreased. We can directly observe the surface crystallization of NH₄NO₃ by FM. The results revaled that C₂₂N₃COO^- monolayer was the promoter of NH₄NO₃ surface crystallization. In contrast,DOPC monolayer was the inhibitor of the surface crystallization of NH₄NO₃.